center point in camera view
Get the camera-object direction as a vector by subtracting the cameras location from the objects location: direction
Convert this vector to a look at quaternion with the vectors to_track_quat('Z', 'Y') function. This function returns a quaternion rot which points its Z in the direction of the direction vector and its Y in the direction of the global Y.
Convert rot to a 4x4 matrix.
Convert the cameras location into a Translation Matrix and store it in loc.
Compose the new camera matrix by matrix-multiplying the loc matrix and the rot matrix and assign it to the camera matrix_world.




import bpy
import mathutils

cam = bpy.context.scene.camera
object = bpy.context.active_object

direction = cam.location - object.location

rot = direction.to_track_quat('Z', 'Y').to_matrix().to_4x4()
loc = mathutils.Matrix.Translation(cam.location)

cam.matrix_world =  loc @ rot